- try sysrq when halt is not available

diff --git a/build b/build
index 18f9622..6e3f1d3 100755 (executable)
--- a/build
+++ b/build
@@ -226,7 +226,12 @@ cleanup_and_exit () {
        sleep 1                # wait till tee terminates
        if test "$VM_TYPE" != lxc; then
            kill -9 -1        # goodbye cruel world
-           exec /bin/bash -c 'mount -n -o remount,ro / ; halt -f -p'
+           if ! test -x /sbin/halt ; then
+               mount -n -tproc none /proc
+               sync
+               sleep 2 # like halt does
+               test -e /proc/sysrq-trigger && echo o > /proc/sysrq-trigger
+           fi
            halt -f -p
        fi
     else